Cyclotron resonance of localized electrons in n-type Cd-Mn-Se

Electron cyclotron resonance has been observed in a wide-gap semiconductor Cd1-xMnxSe at helium temperatures where practically all electrons are bound on donors. The number of electrons participating in the cyclotron resonance absorption of far-infrared radiation increases rapidly as the resonance magnetic field is raised from 1.5 to 5 T. The origin of the implied extended electronic states is attributed to an Anderson-type transition in clusters of donors of higher than average concentration and volume which is greater than (4/3) (magnetic length)3, resulting from random fluctuations of local donor density.